1. Field of the Invention
The invention relates to the collecting of radiant solar energy and more particularly to the concentrating type of solar energy collection.
2. Description of Prior Art
Concern about the limits of conventional energy sources has created renewed interest in one of the oldest areas of energy technology, the collection and use as heat of solar energy. To mention some of the existing solar energy collection systems, there are flat plate collectors used as solar stills; cylindrical and parabolic collector troughs; conical concentrators and sun-following paraboloidal concentrators.
Simple flat plate collectors in widespread use for domestic water heating require favorable climatic conditions, and roof-mounted collectors for house heating in temperate climates have not been found to be economical because of the high cost of such collectors and their low temperature operation.
More advanced systems, such as the concentrating collector which has an expensive extruded Fresnel lens and which is mounted to track the sun about a fixed inclined axis yield higher temperature heat, but the cost and the required insulation of such systems are the drawbacks. Solar refrigeration using high-temperature collectors has long been desired, but economic problems and intermittent operation have resulted in use restricted primarily to experimental installations.
There remains a need for a relatively inexpensive yet efficient solar collector system that can be used in a wide range of climatic conditions.